Pivot arrangement for a motorized device

ABSTRACT

In the exemplary embodiment, an electric rotary fan has a fan head including a rotary motor and a fan blade, the fan blade rotated by the motor for producing an air stream. A pair of rubber bushings are each disposed between the fan head and a stand and each have a hole though the bushing and a key displaced from the hole, the holes of both bushings being coaxially aligned on a horizontal pivot axis. A pair of fasteners each pass through the associated bushing&#39;s hole to affix the fan head to the stand such that each fastener and its associated bushing cooperate to allow forced pivoting of the fan head relative to the stand the pivot about the pivot axis. The keys prevent relative pivoting between the bushings and the fan head by each engaging a mating tab hole in the fan head.

FIELD OF THE INVENTION

The present invention is related to electric apparatuses having a motorized head portion pivotably attached to a stationary base portion, such as but not limited to an electrical fan. More specifically, the present invention is related to a selectively pivotable connection arrangement between the head and base portions of such an electrical apparatus, where the motor rotation in the head portion causes vibrations and gyroscopic effects that would otherwise alter the selected and desired relationship between the head and base portions.

BACKGROUND

Electrical Rotary Fans are well known and commonly used for room cooling. It is very common in the prior art that such fans employ a motorized fan head portion supported on a base portion. It is very common that such fans employ some sort of pivot arrangement at the connection of the head portion to the base portion so that the head portion may be selectively pivoted up and down and/or side to side relative to the base portion, to thereby selectively direct the airflow streaming from the head portion.

Because fan motors tend to be heavy, and because rotating fans create a gyroscopic effect, and because rotating fans tend to vibrate, the simpler of such prior art pivot arrangements have suffered from an inability to maintain the selected head/base relationship. The more functional of such prior art pivot arrangements have suffered from complicated assembly of numerous components, expense in manufacturing, and non-reliability.

U. S. Pat. Nos. 5,431,544 and 6,293,755 exemplify such complicated attempts to allow selective positioning of a fan's head portion relative to its base portion such that the selected relationship will be maintained under operating conditions.

There exists a need for improvement in the reliability and functionality of pivot arrangements between fan heads and stationary bases, and such is an object of the present invention.

There exists a need for reduction in the complicated assembly of reliably functional pivot arrangements between fan heads and stationary bases, and such is an object of the present invention.

There exists a need for reduction in the number of components in reliably functional pivot arrangements between fan heads and stationary bases, and such is an object of the present invention.

There exists a need for similar benefits in other motorized appliances, and such is an object of the invention.

Further needs and objects exist, which are addressed by the present invention, as may become apparent by the included disclosure of an exemplary embodiment thereof.

SUMMARY OF THE INVENTION

In one exemplary embodiment, the invention may be practiced in a fan having a fan head including a rotary motor and a fan blade, the fan blade rotated by the motor for producing an air stream. A bushing is disposed between the fan head and a stationary support, preferably in the form of a stand. The bushing includes a pivot and a key displaced from the pivot. The key is configured to prevent relative pivoting between the bushing and the fan head. The key may alternatively be configured to prevent relative pivoting between the bushing and the support.

A fastener affixes the fan head to the support via the pivot of the bushing such that the fastener and bushing cooperate to allow forced pivoting and to deny non-forced pivoting of the fan head relative to the support about the pivot.

The pivot may include a pivot hole though the bushing and the fastener may pass through the pivot hole to affix the fan head to the support. The bushing is preferably made of a rubber-like material, such as rubber or a rubber-like polymer.

The key may be a tab and may be configured to prevent relative pivoting between the bushing and the fan head by engaging a mating tab hole in the fan head. The tab may alternatively be configured to prevent relative pivoting between the bushing and the support by engaging a mating tab hole in the support.

The fastener may compress the bushing to cause frictional interference between the fan head, the bushing, and the support, to thereby deny non-forced pivoting of the fan head relative to the support. The pivot may be disposed about a pivot axis and the forced pivoting of the fan head relative to the support may be about the pivot axis. The pivot axis is preferably horizontally disposed.

The support may have a clearance hole aligned with the pivot axis and the fan head may have a threaded hole aligned with the pivot axis, and the fastener may be an elongate screw passing through the clearance hole and pivot hole and threadedly engaging the threaded hole to affix the fan head to the support.

The invention may also be practiced in a fan having a fan head including a rotary motor and a fan blade, the fan blade rotated by the motor for producing an air stream. Each of a pair of bushings is disposed between the fan head and a support, preferably in the form of a stand. The bushings each include a pivot and a key displaced from the pivot. The keys are each configured to prevent relative pivoting between the bushing and the fan head, the pivots of both bushings being coaxially aligned. The keys may alternatively each be configured to prevent relative pivoting between the bushing and the support.

A pair of fasteners each affix the fan head to the support via the pivot of one of the bushings such that each fastener and its associated bushing cooperate to allow forced pivoting and to deny non-forced pivoting of the fan head relative to the support about the pivot.

The pivots may each include a pivot hole though the bushing and the fasteners may each pass through one of the pivot holes to affix the fan head to the support. The bushings are each preferable made of a rubber-like material, such as rubber or a rubber-like polymer.

Each key may be a tab and may be configured to prevent relative pivoting between the bushing and the fan head by engaging a mating tab hole in the fan head. The tabs may alternatively be configured to prevent relative pivoting between the bushings and the support by engaging mating tab holes in the support.

Each fastener may compress the associated bushing to cause frictional interference between the fan head, the associated bushing, and the support, to thereby deny non-forced pivoting of the fan head relative to the support. The pivots may both be disposed about a single pivot axis and the forced pivoting of the fan head relative to the support may be about the pivot axis. The pivot axis may be horizontally disposed.

The support may have a pair of clearance holes aligned with the pivot axis and the fan head may have a pair of threaded holes aligned with the pivot axis, and the fasteners may each be an elongate screw passing through one of the clearance holes and one of the pivot holes and threadedly engaging one of the threaded holes to affix the fan head to the support.

The invention may also be practiced in a combination of a fan head, a stationary stand, a pair of rubber bushings, and a pair of fasteners. The fan head may include a guard surrounding and supporting a rotary motor and a fan blade, the fan blade rotated by the motor for producing an air stream.

Each of the pair of rubber bushings may be disposed between the fan head and the stand and each may have a hole though the bushing and a key displaced from the hole, the holes of both bushings being coaxially aligned on a horizontal pivot axis. The pair of fasteners may each pass through the associated bushing's hole to affix the fan head to the stand such that each fastener and its associated bushing cooperate to allow forced pivoting of the fan head relative to the stand the pivot about the pivot axis.

Each key may be a tab and may be configured to prevent relative pivoting between the bushing and the fan head by engaging a mating tab hole in the fan head. Each fastener may compress the associated bushing to cause frictional interference between the fan head, the associated bushing, and the stand, to thereby deny non-forced pivoting of the fan head relative to the stand. The stand may include a pair of clearance holes aligned with the horizontal pivot axis and the fan head may include a pair of threaded holes aligned with the horizontal pivot axis. The fasteners may each be an elongate screw passing through one of the clearance holes and one of the pivot holes and threadedly engaging one of the threaded holes to affix the fan head to the stand.

The combination may further include a pair of nuts, and the guard may be molded polymer and may include a pair of integrally molded rectangular slots each for receiving one of the nuts and preventing rotation thereof, and the threaded holes may be disposed in the nuts.

Further features and aspects of the invention are disclosed with more specificity in the Detailed Description and Drawings of the exemplary embodiments provided therein.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the invention can be better understood with reference to the included drawings. The components in the drawings are not necessarily to scale, and all components may not be present in all views, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is a perspective view of an electric rotary fan having a head-to-base pivot arrangement in accordance to a first embodiment of the invention;

FIG. 2 is a partial exploded view of the pivot arrangement of the fan of FIG. 1;

FIG. 3 is a partial cross-sectional view through the pivot arrangement of the fan of FIG. 1;

FIG. 4 is a perspective view of the pivot bushing of the pivot arrangement of the fan of FIG. 1;

FIG. 5 is a left side view of the fan of FIG. 1;

FIG. 6 is a left side view of the fan of FIG. 1 with its head portion pivoted slightly upwardly relative to its base portion;

FIG. 7 is a left side view of the fan of FIG. 1 with its head portion pivoted significantly upwardly relative to its base portion;

FIG. 8 is a right side view of the fan of FIG. 1;

FIG. 9 is a partial exploded view of an electric rotary fan having a head-to-base pivot arrangement in accordance to a second embodiment of the invention; and

FIG. 10 is a partial cross-sectional view through the pivot arrangement of the fan of FIG. 8.

DETAILED DESCRIPTION

Reference is now made to FIGS. 1 through 10, where there are shown electric fans having pivot arrangements in accordance with just two of the infinite number of possible embodiments of the present invention.

In FIGS. 1 through 8, fan 100 has fan head 102, a stand 114, and two pivot bushings 134. Fan head 102 includes rear guard 104, front guard 106, rotary motor 108, and fan blade 110. Motor 108 is rigidly mounted to rear guard 104, and has a rotating motor shaft projecting forwardly there-from (not shown) to which fan blade 110 is affixed so that rotation of the motor shaft cause rotation of the fan blade and results in a forwardly directed airstream. Front guard 106 is affixed by fasteners (not shown) to rear guard 104 to form a perforated enclosure around the rotating fan blade, to protect users from dangerously accessing the blade while still allowing the intended airstream to flow through and from the fan blade and fan.

Stand 114 is made of tubular metal and includes a base portion 116 having feet 118 for resting on a supporting surface, such as a floor or table, and has two upright support posts 119, each with an upper terminus having a support hole 120. The support holes of the two support posts lie coaxially on a horizontal pivot axis 124.

Rear Guard 104 has a pair of panels 126L and 126R, each the mirror image of the other, and each integrally formed with or permanently affixed to an opposite side of the rear guard, along the top to bottom midpoint of the rear guard. The panels each include a threaded hole 128 and a square key hole 130. The threaded holes of each panel are coaxially aligned and lie on a line that preferably passes through the center of gravity of the fan head.

Pivot bushings 134 are identical, and each made of a rubber-like polymer and include a tubular potion 136 with a through hole 138, and a tab portion 140 having a square key 144 projecting there-from. When properly oriented, the through hole and key project horizontally. The key is sized to be inserted into and to fit closely within one of the square key holes 130 of the rear guard. When so inserted, the bushing's through hole is coaxially aligned with the adjacent threaded hole 128, as best seen in FIGS. 2 and 3.

The upright support posts 119 of the stand are spaced apart to receive the fan head 102 with the pivot bushings 134 inserted therein, such that the though holes 138 or the bushings and the threaded holes 120 of the rear guard are disposed along the horizontal pivot axis 124. Threaded screws 146 are inserted through the support holes 120, through holes 138, and threaded into threaded holes 120 to secure each of the upright supports to the fan head. The screws are preferably tightened into the threaded holes sufficiently to create a slight amount of compression on the rubber bushings.

Referring now to FIGS. 5 through 7, it can be seen how the fan head 102 may be selectively pivoted about the horizontal pivot axis 124 relative to the stand 114, which is accomplished by applying a pivoting force to the fan head. During such forced pivoting, the compression of the rubber-like bushings between the fan head and stand creates a position-holding tightness on the pivot axis, while also providing a vibration and sound isolating effect through the rubber-like bushings. The interface between each bushing's key and each panel's square key hole prevents rotation of the bushing relative to the fan head, which is found to prevent inadvertent and undesirable tilting of the fan head during operation, as it is want to do as a result of the weight of the fan head and its motor, and as a result of the gyroscopic inertia and vibration of the rotating components.

Because the motor is relatively dense and heavy, and rotation of the fan blade causes both vibration and gyroscopic effects such that even the most careful positioning of the horizontal pivot axis through the fan head's center of gravity would otherwise be insufficient to maintain the selected fan heat tilt position by the compressive forces on the bushings alone. It is found that, absent the keying of the present invention, sufficient compression of the bushings to prevent inadvertent tilting would result in such a tight pivot arrangement as to make the forces required for intentional tilting impractically excessive.

It is found that because only a slight amount of compression of the bushings is required by this arrangement, damage to and excessive wearing of the bushings is avoided, and a much easier tilting force may be applied that would otherwise be required.

While the rear guard 104 of fan 100 is preferably made of metal, such as steel wires and plates welded together, FIGS. 9 and 10 show a second fan 200 in accordance with the invention, otherwise identical to fan 100 except that its rear guard 204 is molded of polymer, such that each panel 226 and square key hole 230 are molded integrally therein. In substitution for the threaded holes of the first embodiment, clearance holes 228A are provided in combination with an additional threaded steel nut 228B. A slot 228C is integrally formed into the rear guard to receive the nut such that its threaded hole 228D is coaxially aligned with the clearance hole. The slot is sized to grasp opposing flats of the nut to prevent its rotation during the threaded insertion and tightening of screw 146 though stand 114 and bushing 134.

While the invention has been shown and described with reference to a specific exemplary embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention, and that the invention should therefore only be limited according to the following claims, including all equivalent interpretation to which they are entitled. 

1. A fan comprising: a fan head comprising a rotary motor and a fan blade, the fan blade rotated by the motor for producing an air stream; a stationary support; a bushing disposed between the fan head and the support and comprising a pivot and a key displaced from the pivot and configured to prevent relative pivoting between the bushing and one of the fan head and the support; and a fastener affixing the fan head to the support via the pivot of the bushing such that the fastener and bushing cooperate to allow forced pivoting and to deny non-forced pivoting of the fan head relative to the support about the pivot.
 2. The fan of claim 1 wherein the pivot comprises a pivot hole though the bushing and the fastener passes through the pivot hole to affix the fan head to the support.
 3. The fan of claim 2 wherein the bushing is comprised of a rubber-like material.
 4. The fan of claim 3 wherein the key is a tab and is configured to prevent relative pivoting between the bushing and one of the fan head and the support by engaging a mating tab hole in the one of the fan head and the support.
 5. The fan of claim 4 wherein the one of the fan head and support is the fan head.
 6. The fan of claim 5 wherein the fastener compresses the bushing to cause frictional interference between the fan head, the bushing, and the support, to thereby deny non-forced pivoting of the fan head relative to the support.
 7. The fan of claim 6 wherein the support comprises a stand.
 8. The fan of claim 7 wherein the pivot is disposed about a horizontal pivot axis and the forced pivoting of the fan head relative to the support is about the horizontal pivot axis.
 9. The fan of claim 8 wherein the support comprises a clearance hole aligned with the horizontal pivot axis and the fan head comprises a threaded hole aligned with the horizontal pivot axis, and the fastener is an elongate screw passing through the clearance hole and pivot hole and threadedly engaging the threaded hole to affix the fan head to the support.
 10. A fan comprising: a fan head comprising a rotary motor and a fan blade, the fan blade rotated by the motor for producing an air stream; a stationary support; each of a pair of bushings disposed between the fan head and the support and each comprising a pivot and a key displaced from the pivot and configured to prevent relative pivoting between the bushing and one of the fan head and the support, the pivots of both bushings being coaxially aligned; and a pair of fasteners each affixing the fan head to the support via the pivot of one of the bushings such that each fastener and its associated bushing cooperate to allow forced pivoting and to deny non-forced pivoting of the fan head relative to the support about the pivot.
 11. The fan of claim 10 wherein the pivots each comprise a pivot hole though the bushing and the fasteners each pass through one of the pivot holes to affix the fan head to the support.
 12. The fan of claim 11 wherein the bushings are each comprised of a rubber-like material.
 13. The fan of claim 12 wherein each key is a tab and is configured to prevent relative pivoting between the bushing and one of the fan head and the support by engaging a mating tab hole in the one of the fan head and the support.
 14. The fan of claim 13 wherein the one of the fan head and support is the fan head.
 15. The fan of claim 14 wherein each fastener compresses the associated bushing to cause frictional interference between the fan head, the associated bushing, and the support, to thereby deny non-forced pivoting of the fan head relative to the support.
 16. The fan of claim 15 wherein the support comprises a stand.
 17. The fan of claim 16 wherein the pivots are both disposed about a single horizontal pivot axis and the forced pivoting of the fan head relative to the support is about the horizontal pivot axis.
 18. The fan of claim 17 wherein the support comprises a pair of clearance holes aligned with the horizontal pivot axis and the fan head comprises a pair of threaded holes aligned with the horizontal pivot axis, and the fasteners are each an elongate screw passing through one of the clearance holes and one of the pivot holes and threadedly engaging one of the threaded holes to affix the fan head to the support.
 20. In combination: a fan head comprising a guard surrounding and supporting a rotary motor and a fan blade, the fan blade rotated by the motor for producing an air stream; a stationary stand; each of a pair of rubber bushings disposed between the fan head and the stand and each comprising a hole though the bushing and a key displaced from the hole, the holes of both bushings being coaxially aligned on a horizontal pivot axis; and a pair of fasteners each passing through the associated bushing's hole to affix the fan head to the stand such that each fastener and its associated bushing cooperate to allow forced pivoting of the fan head relative to the stand the pivot about the pivot axis; wherein each key is a tab and is configured to prevent relative pivoting between the bushing and the fan head by engaging a mating tab hole in the fan head; wherein each fastener compresses the associated bushing to cause frictional interference between the fan head, the associated bushing, and the stand, to thereby deny non-forced pivoting of the fan head relative to the stand; and wherein the stand comprises a pair of clearance holes aligned with the horizontal pivot axis and the fan head comprises a pair of threaded holes aligned with the horizontal pivot axis, and the fasteners are each an elongate screw passing through one of the clearance holes and one of the pivot holes and threadedly engaging one of the threaded holes to affix the fan head to the stand.
 21. The combination of claim 20 further comprising a pair of nuts, wherein the guard is molded polymer and comprises a pair of integrally molded rectangular slots each for receiving one of the nuts and preventing rotation thereof, and the threaded holes are disposed in the nuts. 